1. Field of the Invention
This invention generally relates to the field of surgical instruments, and more particularly to rongeurs for cutting and removing tissue, bone and the like during surgery.
2. Description of Related Art
Ronguers are used to excise tissue, degenerated disc materials or bone during surgical procedures. During regular use, tissue, blood, or other fluids collect in the voids between the top and bottom shafts of the instrument Multiple uses result in a buildup of material. To clean a rongeur thoroughly it must be disassembled.
Most rongeurs made today cannot easily be disassembled after surgery, and therefore cannot thoroughly be cleaned. The preferred method of cleaning surgical instruments is an ultrasonic cleaner. Ultrasonic cleaners cannot remove debris, e.g., blood, tissue or other buildups or deposits from inside the shaft, while the shaft is closed.
A typical prior art rongeur is shown in FIGS. 1A-1D. Springs 107, 108 act to spread apart front handle piece 106 from the handle portion 118 of bottom shaft 102, pivoting about the shank of screw 103. Top shaft 101 is slidably positioned over bottom shaft 102 by means of alignment guides 112, 114 attached to top shaft 101 which fit into channels 113, 115 in bottom shaft 102 and are held in place by channel constrictions, one of which (119) is shown. Top shaft 101 is slidably driven forward and backward by the pivoting movement of front handle piece 106, the driving slot (116) of which engages driving pin 117 in top shaft 101 to supply the driving force thereto.
When handles 106, 118 are not being squeezed, the action of springs 107 and 108 results in top shaft 101 being fully retracted toward the rear of the instrument. The gap 110 in front of top shaft 101 in this position is called the "bite opening." The front 111 of top shaft 101 and "foot plate" 105 against which it touches when handles 106, 118 are fully compressed, are cutting surfaces. When these cutting surfaces contact, they "bite," and thus remove material held in the bite opening. Rongeurs are available in a variety of foot plate profiles and bite opening dimensions, as well as in different sizes and configurations of the handles and shafts. Typically, a range of different rongeurs will be available to a surgeon for use during a surgical procedure.
Most prior art rongeurs require tools to disassemble and are difficult to reassemble. The following are the steps necessary to disassemble a typical prior art rongeur such as the one shown in FIGS. 1A-1D.
Most prior art rongeurs require tools to disassemble and are difficult to reassemble. The following are the steps necessary to disassemble a typical prior art rongeur such as the one shown in FIGS. 1A-1D.
Loosen screws (104 etc.) holding springs 107, 108 (stripping is likely, ruins the screws) PA1 Loosen and remove screw 103 PA1 Pull front handle piece 106 down, disengaging driving slot 116 from driving pin 117 PA1 Slide top shaft 101 back, disengage alignment guides 112, 114 from channels 113,115, and remove, PA1 Select matching parts for the rongeur being reassembled PA1 Reseat alignment guides 112, 114 protruding from top shaft 101 in channels 113, 115 in bottom shaft 102 PA1 Align top shaft 101 so that driving pin 117 is opposite position where driving slot 116 will reinsert (easy to mistake correct position) PA1 Insert screw 103 and tighten PA1 Align springs 107, 108 together (and tighten screw 104 and opposing screw (not shown), if necessary), PA1 1. Tools are required, screws must be taken out which are not meant to be removed. It is very easy to strip a screw or cause burrs on the screw head. This can lead to a dangerous situation in the operating room if a surgeon's glove is torn by burrs on the screw head. PA1 2. When rongeurs are disassembled the instrument is in a number of parts (e.g., 101, 102, 106, 107, 108, 109, etc.), which can be easily lost or misplaced during the cleaning process. PA1 3. Rongeurs are used in sets with varying sizes of tips and shaft lengths. Parts from different rongeurs can be confused, resulting in an improperly reassembled instrument that malfunctions, binds or comes apart. PA1 4. Putting rongeurs back together requires training. A rongeur that is not properly reassembled may fail in the operating room causing possible injury to the patient, valuable time loss during the procedure, and damage to the instrument. PA1 An instrument that can be opened, allowing an ultrasonic cleaner to clean the entire instrument effectively. PA1 An instrument that stays together in one piece, thereby avoiding loose parts that can be lost. PA1 An instrument that, after being opened and cleaned, can be reassembled by a novice without the use of tools. PA1 An instrument that, after reassembly, reliably functions as intended. PA1 An openable yet unitary instrument that has no functional disadvantage as compared to prior art rongeur designs.
The following are the steps necessary to reassemble such a prior art rongeur.
Note that in reassembly, there is no positive indication of proper position. In addition, the slot of screw 103, and possibly other screws, will burr with repeated removal, resulting in holes in gloves and injury.
In summary, the problems encountered with disassembling prior art rongeurs include the following:
Due to these problems, a need was perceived to devise a new rongeur that would overcome the problems noted above, but without compromising any of the utility of prior art rongeurs.